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Finding the Fourth Proportional to 280.20, 419.70 and 172.20

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Solution

The fourth proportional to 280.20, 419.70 and 172.20 is: 257.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.20 : 419.70 = 172.20 : x
  2. Step 2: Convert to fraction form
    280.20/419.70 = 172.20/x
  3. Step 3: Cross multiply
    280.20x = 419.70 × 172.20
  4. Step 4: Simplify right side
    280.20x = 72,272.34
  5. Step 5: Solve for x
    x = 72,272.34/280.20
  6. Step 6: Final answer
    x = 257.93

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.